From: Qingfang Deng <qingfang.deng@linux.dev>
To: Breno Leitao <leitao@debian.org>
Cc: Norbert Szetei <norbert@doyensec.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Taegu Ha <hataegu0826@gmail.com>, Kees Cook <kees@kernel.org>,
linux-ppp@vger.kernel.org, linux-kernel@vger.kernel.org,
Guillaume Nault <gnault@redhat.com>,
netdev@vger.kernel.org
Subject: Re: [PATCH net v2] ppp: defer channel free to an RCU grace period to fix pppol2tp RX UAF
Date: Sun, 5 Jul 2026 10:57:44 +0800 [thread overview]
Message-ID: <87111f02-5b7a-4185-8364-2faba650578b@linux.dev> (raw)
In-Reply-To: <akfjpBVML_1RFF91@gmail.com>
On 7/4/2026 at 12:32 AM, Breno Leitao wrote:
> On Fri, Jul 03, 2026 at 03:27:00PM +0800, Qingfang Deng wrote:
>> AI-review found an issue: https://sashiko.dev/#/patchset/D9C0245B-608B-4884-8A09-F55BA4A9F948%40doyensec.com
>>
>> An rcu_barrier() call is needed at the end of ppp_cleanup().
>
> I was initially unclear why rcu_barrier() would be necessary on a kfree path,
> but it appears to be required during module unload to ensure that
> ppp_release_channel_free() completes before the module's struct rcu_head is
> destroyed. Is that the correct understanding?
It's required to ensure that all ppp_release_channel_free() callback
complete before the text segment of the module is unloaded.
next prev parent reply other threads:[~2026-07-05 2:58 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-01 18:12 [PATCH net v2] ppp: defer channel free to an RCU grace period to fix pppol2tp RX UAF Norbert Szetei
2026-07-02 8:19 ` Qingfang Deng
2026-07-03 16:05 ` Guillaume Nault
2026-07-03 7:27 ` Qingfang Deng
2026-07-03 16:32 ` Breno Leitao
2026-07-05 2:57 ` Qingfang Deng [this message]
2026-07-06 9:29 ` Sebastian Andrzej Siewior
2026-07-06 7:22 ` Norbert Szetei
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